The present embodiments relate to a circuit for providing an AC signal and a method for operating the circuit.
A square-wave signal may be used as a clock signal or an oscillator signal for different electronic applications. With this in view, effort is frequently directed at realizing a maximally symmetric pulse-pause ratio. A given signal is initially sinusoidal with a low amplitude. The signal is amplified using a logic gate and converted into a square-wave signal. For example, an input of the logic gate may be forward-biased via a resistor for this purpose to approximately half of an operating voltage.
The problem that exists is that if the sinusoidal signal is switched off at the input of the logic gate or if the amplitude of the sinusoidal signal is too low, an output of the logic gate has no stable state (either logic “0” or logic “1”, also referred to as “low” or “high” potential). Instead, the output of the logic gate may oscillate in an undefined manner between the two logic states. For example, the logic gate will oscillate unpredictably in the MHz or GHz range.